The compounds of formula (I), as defined below, can be useful as perfuming ingredients and/or as starting material for the synthesis of compounds having a more complex skeleton.
The methods of preparation of said compounds reported in the prior art are in general quite long and/or expensive.
It is therefore highly desirable to access such compounds by means of a simple and efficient isomerisation process wherein the starting material is an easily accessible material. To the best of our knowledge, in the prior art there is no report of an isomerisation process giving a direct access to compounds of formula (I) from the compound of formula (II).